Add the detailed info for parameter 'verbose' (#1435)

* explain-verbose-parameter

* concise-verbose-docstring

* explain-verbose-parameter

* explain-verbose-parameter

* test-ignore

* test-ignore

* sklearn-version-califonia

* submit-0526

---------

Co-authored-by: Runlin Mu (FESCO Adecco Human Resources) <v-runlinmu@microsoft.com>
Co-authored-by: Li Jiang <bnujli@gmail.com>

Author: 3 people

flaml/automl/automl.py

@@ -192,6 +192,12 @@ def custom_metric(
                 Only valid for sequential search.
             verbose: int, default=3 | Controls the verbosity, higher means more
                 messages.
+                verbose=0: logger level = CRITICAL
+                verbose=1: logger level = ERROR
+                verbose=2: logger level = WARNING
+                verbose=3: logger level = INFO
+                verbose=4: logger level = DEBUG
+                verbose>5: logger level = NOTSET
             retrain_full: bool or str, default=True | whether to retrain the
                 selected model on the full training data when using holdout.
                 True - retrain only after search finishes; False - no retraining;
@@ -1350,6 +1356,12 @@ def custom_metric(
                 for training data.
             verbose: int, default=3 | Controls the verbosity, higher means more
                 messages.
+                verbose=0: logger level = CRITICAL
+                verbose=1: logger level = ERROR
+                verbose=2: logger level = WARNING
+                verbose=3: logger level = INFO
+                verbose=4: logger level = DEBUG
+                verbose>5: logger level = NOTSET
             retrain_full: bool or str, default=True | whether to retrain the
                 selected model on the full training data when using holdout.
                 True - retrain only after search finishes; False - no retraining;